/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.coders;



import com.bff.gaia.unified.sdk.values.TypeDescriptor;



import java.io.*;



/** A {@link ByteCoder} encodes {@link Byte} values in 1 byte using Java serialization. */

public class ByteCoder extends AtomicCoder<Byte> {



  public static ByteCoder of() {

    return INSTANCE;

  }



  /////////////////////////////////////////////////////////////////////////////



  private static final ByteCoder INSTANCE = new ByteCoder();

  private static final TypeDescriptor<Byte> TYPE_DESCRIPTOR = new TypeDescriptor<Byte>() {};



  private ByteCoder() {}



  @Override

  public void encode(Byte value, OutputStream outStream) throws IOException, CoderException {

    if (value == null) {

      throw new CoderException("cannot encode a null Byte");

    }

    outStream.write(value);

  }



  @Override

  public Byte decode(InputStream inStream) throws IOException, CoderException {

    try {

      // value will be between 0-255, -1 for EOF

      int value = inStream.read();

      if (value == -1) {

        throw new EOFException("EOF encountered decoding 1 byte from input stream");

      }

      return (byte) value;

    } catch (EOFException | UTFDataFormatException exn) {

      // These exceptions correspond to decoding problems, so change

      // what kind of exception they're branded as.

      throw new CoderException(exn);

    }

  }



  /**

   * {@inheritDoc}

   *

   * <p>{@link ByteCoder} will never throw a {@link Coder.NonDeterministicException}; bytes can

   * always be encoded deterministically.

   */

  @Override

  public void verifyDeterministic() {}



  /**

   * {@inheritDoc}

   *

   * @return {@code true}. This coder is injective.

   */

  @Override

  public boolean consistentWithEquals() {

    return true;

  }



  /**

   * {@inheritDoc}

   *

   * @return {@code true}. {@link ByteCoder#getEncodedElementByteSize} returns a constant.

   */

  @Override

  public boolean isRegisterByteSizeObserverCheap(Byte value) {

    return true;

  }



  @Override

  public TypeDescriptor<Byte> getEncodedTypeDescriptor() {

    return TYPE_DESCRIPTOR;

  }



  /**

   * {@inheritDoc}

   *

   * @return {@code 1}, the byte size of a {@link Byte} encoded using Java serialization.

   */

  @Override

  protected long getEncodedElementByteSize(Byte value) throws Exception {

    if (value == null) {

      throw new CoderException("cannot estimate size for unsupported null value");

    }

    return 1;

  }

}